• Rickets is a preventable bone disease that causes weak, soft bones. If a child has softer bones, the bones can bend and become an abnormal shape. Rickets only occurs in growing bones, so it mostly occurs in infants and young children, but it can also occur in teenagers. It is most common when children are growing quickly.   

    Rickets is usually caused by low vitamin D, especially if children also have low calcium or low phosphate intake. Calcium and phosphate are minerals that are mostly found in milk and dairy foods, and they are important for healthy, strong bones.

    Rickets is not common. Nearly all cases of rickets in Australia occur in infants and children who have migrated to Australia, or whose parents migrated to Australia. The risk factors for rickets are the same as the risk factors for low vitamin D. There are conditions associated with inherited forms of rickets, but these are extremely rare. Sometimes kidney problems cause rickets by affecting how the body handles vitamin D, calcium and phosphate.

    Signs and symptoms of rickets

    If your child has rickets, they may have:

    • legs that are an abnormal shape (most commonly 'bow-legs' but can also be 'knock-knees' - it is normal to have some bowing before two years old and some knock-knees around the age of four)
    • swelling at the wrists, knees and ankles because the ends of the bones are larger than normal
    • late tooth eruption (appearance) and problems with tooth enamel
    • late closure of the fontanelle (the soft part on top of a baby's head)
    • soft skull bones (craniotabes)
    • poor growth
    • late crawling and walking
    • bone fractures after minor falls or traumas.

    Infants and children with rickets are often grumpy and irritable because their bones are sore. Sometimes babies with rickets can have symptoms of very low calcium levels, such as muscle cramps or seizures. Seizures from low calcium mostly happen in babies who are less than one year old (but can occur in older children too).

    When to see a doctor

    If your child has any of the symptoms of rickets, or the symptoms of low calcium levels, take them to a GP as soon as possible. Your child will be referred to see a specialist urgently.

    The specialist will have your child undertake blood tests (to check vitamin D, calcium balance, phosphate, kidney function, and bone turnover), urine tests and X-rays.

    • Children with very low calcium (including children with seizures) will need admission to hospital to have extra calcium and heart monitoring, because low calcium levels can affect many parts of the body, including the heart.
    • Rickets caused by low vitamin D is treated by vitamin D supplements. Often children will need extra calcium and phosphate as well, by increasing dairy foods or by taking supplements. Vitamin D tablets or mixtures can be low dose (taken daily) or high dose (taken monthly or less often). It is important to check calcium balance first – sometimes children will need extra calcium and/or phosphate before they have high doses of vitamin D.
    • Rickets caused by inherited diseases or kidney problems is managed by specialist kidney (renal) and hormone (endocrine) doctors.

    How can rickets be prevented?

    Although rickets is usually caused by low vitamin D, most children with low vitamin D do not get rickets. Rickets is more likely in babies and children who also have low dairy intake, and in babies who breastfeed for a long time without starting solid foods at the normal age (around four to six months).

    For children (or unborn babies) at risk of low vitamin D, rickets can be prevented by: 

    • making sure women have good vitamin D levels during pregnancy
    • identifying babies who are at risk of low vitamin D (fully breastfed babies with at least one other risk factor such as dark skin) and starting vitamin D supplements (400 IU daily) from birth and continuing until they are at least one year old
    • introducing solid foods for babies when they are four to six months old
    • identifying and treating low vitamin D
    • spending time outside to prevent low vitamin D
    • making sure children and adolescents have enough calcium and phosphate in their diets (two to three serves of dairy each day) – one serve of dairy is one glass of milk or one tub of yoghurt or one slice of cheese. If your child has a dairy allergy, talk to your doctor or nutritionist about alternatives.

    Including foods with vitamin D in your child's diet may help prevent rickets. Foods with vitamin D include fresh fatty fish (e.g. salmon, herring, mackerel and sardines), liver, some mushrooms and egg yolks. Some foods have vitamin D added, such as margarine and some breakfast cereals or dairy products.

    However, foods only provide a small amount (10 per cent or less) of daily vitamin D needs for most people in Australia, and safely spending enough time in the sun is the best way to prevent low vitamin D. See our fact sheet Vitamin D.

    Children with dark skin who live in the southern parts of Australia should have extra vitamin D supplements during winter.


    Regular follow-up with a paediatrician is needed to ensure that healthy levels of vitamin D, calcium and phosphate are maintained. You child will have:

    • regular blood tests to measure vitamin D levels 
    • regular X-rays to look at bone growth 
    • a review by a dietitian to ensure that their diet contains all the right food groups.

    Key points to remember

    • Rickets is a disease where bones are weak and soft.
    • It is caused by not having enough vitamin D, and sometimes children with rickets also have low calcium or phosphate levels.
    • It can be prevented and treated by having daily safe sun exposure, and by eating foods that contain vitamin D and calcium.

    For more information

    • Kids Health Info fact sheet: Vitamin D
    • Kids Health Info fact sheet: Sun safety 
    • The Royal Children’s Hospital Immigrant Health Vitamin D resources (available in different languages)
    • See your GP, paediatrician or Maternal and Child Health Nurse.

    Common questions our doctors are asked

    If my child has bow legs, will they straighten up once she is getting more vitamin D?

    Usually, within three months of treatment, an improvement in bone health and shape are visible on X-rays. With medical treatment alone, most bow legs improve dramatically and surgery is not necessary. If there is insufficient straightening, your child will be referred to a bone specialist (orthopaedic surgeon) for review.

    If my child has rickets are they likely to have bone problems later in life?  

    Your child should be monitored closely to make sure they continue to have good vitamin D, calcium and phosphate levels. Once the bone abnormalities are corrected in childhood, your child is not likely to have bone problems later in life. 

    Developed by The Royal Children's Hospital Gastroenterology, General Medicine and Dietetics departments. We acknowledge the input of RCH consumers and carers. 

    Reviewed May 2018. 

    This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

    Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit www.rchfoundation.org.au


This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.